The three-robot act COMPRESSORHEAD — consisting of four-armed drummer Stickboy, guitarist Fingers and bassist Bones — presented a new automatic guitar tuner, in collaboration with the famous guitar producer Gibson, at the Musikmesse Frankfurt 2013 fair, which took place April 10-13 in Frankfurt, Germany. A nine-minute documentary from Harmony Central can be seen below.

"The robots really actually discovered us because we are collectors of new artists and new bands," Borise Loehe of Gibson said. "They like to come to us and like working together with us. And one day the robots knocked on our door and said, 'Man, Gibson is such a great name and we also play Gibsons, should we not maybe work together?' It worked well because we are trying to be innovative and there is a robot technology which we have just built into our guitars, it is a self-thinking guitar which also works with a new technology. So it was clear quite quickly that we said, it all fits together."

COMPRESSORHEAD was created from recycled metal by a technical artist in Berlin, Germany and performs a setlist which includes classic songs from LED ZEPPELIN, MOTÖRHEAD, HELMET, AC/DC and BLACK SABBATH.

"Well, I think it is these special robots which are a bit wilder, a bit edged and angular and also a bit dirty," Loehe said. "This goes well with the music. People are able to identify with this. They had their first concert at a metal festival in Australia and it all fitted perfectly."